Pressure driven apparatus for sequential control of a cementing head

Abstract

A pressure-driven apparatus sequential controls a multiphase operation, e.g., of a cementing head. A transmission arm including a pawl is supported on a cam shaft connected to a pawl cylinder having a built-in return force, directional control valves with a spring return member and roller, operated by the cam plates of the cam shaft, that are staggered relative to each other in a predetermined angle to a pawl disk supported in bearings. The pawl cylinder will rotate cam shaft to a predetermined angular position in the same rotational direction each time the system is supplied with pressure, and operate the directional valves with rollers, whereby the directional valves will apply pressure to actuators present so that cementing valves or other types of valves will open for a predetermined period of time until a timer control shuts off the pressure supply, the pressure is discharged, and the pawl cylinder returns to the starting position thereof. When pressure is supplied to pawl cylinder after all operating phases have been completed, the cam shaft will rotate further on to return to the starting position thereof, and all directional control valves is closed.

The invention claimed is: 
     
       1. A pressure-driven apparatus, for sequential control of a multiphase operation, said apparatus comprising:
 a transmission arm comprising a pawl is supported on a cam shaft connected to a pawl cylinder having a built-in return spring or another return load mechanism; and 
 directional control valves, each direction control valve having a spring return and roller capable of being operated by a cam plate of a plurality of cam plates of the cam shaft the cam plates being staggered relative to each other in a predetermined angle to a pawl disk supported in first and second bearings, 
 wherein the pawl cylinder with the built-in return spring, by the pawl disk, will rotate the cam shaft to a set angle in the same rotational direction each time the apparatus is supplied with pressure, and operate each of the directional control valves using the rollers. 
 
     
     
       2. The pressure-driven apparatus of  claim 1 , wherein on initiation of an operating procedure, no directional control valve of the directional control valves has been operated, and all directional control valves return to a starting position,
 when supplied with pressure, the pawl cylinder rotates the cam shaft forward to a predetermined angular position, whereby a first directional control valve of the directional control valves applies pressure to an actuator and a first cementing valve or another valve opens for a predetermined period of time until a timer control shuts off the pressure supply and the pressure is discharged through a drain valve and the pawl cylinder returns to the starting position, 
 
       the next time pressure is supplied to the pawl cylinder, the cam shaft with the cam plates is rotated further to the predetermined angular position, and a second cementing valve or another valve will open, so that two or more of the cementing valves are open for a predetermined period of time until a timer relay shuts off the pressure supply and the pressure is discharged so that the pawl cylinder returns to the starting position,
 the third and subsequent time(s) pressure is supplied, the cam shaft is rotated in the same rotational direction to a predetermined angular position, and a an additional directional control valve of the directional control valves applies pressure to the actuators, so that the first and second cementing valves open for a predetermined period of time until the timer relay shuts off the pressure supply and the pressure is discharged and the pawl cylinder returns to the starting position, and 
 when pressure is supplied to the pawl cylinder after all operating phases have been completed, the cam shaft is rotated further to the starting position in which all directional valves are in their closed positions.